Merge associations always taking the value that satisfies a given test

Question

I have associations look like this:

data = {<|a -> {2, l1}, b -> {3, l1}|>, <|a -> {3, l2}, b -> {2, l2}|>}

I want the result:

<|a -> {3, l2}, b -> {3, l1}|>

The bigger digit of first value should be left.

Answer 1

Merge[data, First @* MaximalBy[First]]

<|a -> {3, l2}, b -> {3, l1}|>